Pouch for tobacco or tobacco substitute

ABSTRACT

A smokeless tobacco product adapted for oral administration includes a permeable pouch adapted for administration into a user&#39;s mouth and adapted to be removed from the mouth and disposed in nature and smokeless tobacco contained in the pouch. The pouch is made from a degradable polymer whose degradation properties allow the pouch to be essentially intact until the time of disposal and allow the pouch to degrade in nature after disposal.

FIELD OF THE INVENTION

The invention relates generally to smokeless tobacco products, and inparticular to a degradable polymer container for smokeless tobacco.

BACKGROUND OF THE INVENTION

Smokeless tobacco in the form of so-called snuff, i.e. tobacco adaptedfor oral administration, is gaining increased popularity, not least as asubstitute for cigarettes, cigars and other more conventional tobaccoproducts. Although not harmless such smokeless tobacco products pose alesser threat to a user's health than, for example, smoking, and cantherefore be regarded as an acceptable substitute for smoking.

A popular way of administrating snuff is to contain the snuff in apermeable pouch. Such a pouch holds the tobacco in place, while at thesame time letting the flavours and substances of the tobacco passthrough the walls of the pouch and into the user's mouth, to thereby beabsorbed by the mucous membranes. When the flavours and activesubstances are consumed, the user removes the tobacco pouch from his orher mouth and disposes the now moisture-logged pouch.

Due to lack of suitable public bins, or due to the users' indifferenceand indolence, the used tobacco pouches frequently end up in publicplaces, such as streets, at golf courses and other sports grounds, atentrances to public buildings and shops, and so forth. Being small andrelatively flat objects, the tobacco pouches can not easily be picked upand disposed.

Conversely, for a person having a high sense of environmentalresponsibility, the lack of suitable facilities for disposing a usedtobacco pouch may lead to the user keeping the tobacco pouch in his/hermouth longer than he/she actually would like to, thereby exposinghimself/herself to an unnecessary large dose of potentially harmfulagents.

SUMMARY OF THE INVENTION

In the international patent application WO 97/13419 it is mentioned thata degradable sheath could be used to contain smokeless tobacco, but thematerial of the degradable sheath is only briefly discussed.Furthermore, WO 97/13419 is silent about the tactile feeling thatdifferent material compositions evoke in a user's mouth. An appealingtactile sensation is a prerequisite for gaining the consumers'acceptance of smokeless tobacco products.

Consequently, there is still a need for an improved degradable smokelesstobacco container which obviates, or at least reduces, theaforementioned environmental and also medical problems thatnon-degradable tobacco containers present.

Embodiments of the invention are directed to a pouch containingsmokeless tobacco and being adapted for oral administration. Afterremoval from the user's mouth, the pouch will degrade when exposed tothe physical, chemical and biological conditions that prevail indifferent environments around human beings.

One embodiment of the present invention includes a pouch that is madefrom a material which degrades when exposed to humidity over an extendedperiod of time. In a second embodiment the degradation of a pouch ismainly caused by micro-organisms, whereas a pouch according to a thirdembodiment is made from a material that degrades when exposed tosunlight. A still further embodiment degrades due to the influence ofoxygen, i.e. the pouch material degrades via oxidation.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Generally, the invention is directed to a pouch or container adapted tocontain tobacco or a tobacco substitute. The pouch is intended for oraladministration and is designed to degrade in a natural environment afterremoval from the mouth of a user and subsequent disposal. In oneembodiment, the pouch completely surrounds (or encloses) the tobaccowith a material which is not dissolvable in a user's mouth. Duringstorage, the pouch and tobacco therein can be stored in an airtightcontainer (eg, a bag or plastic container) to prevent the pouch frombeing exposed to the oxygen and humidity of ambient air.

In one embodiment of the present invention, the pouch is made from adegradable material, the degradation of which is mainly induced bywater, e.g. in the form of humidity and/or rainwater. Here it should,however, be appreciated that such pouch material will start to degradeas soon as it comes into contact with the tobacco contained in the pouchas tobacco contains a certain amount of moisture. The degradationprocess will then proceed during the entire time of storage before thecorresponding smokeless tobacco product is used by a consumer. Adegradable pouch for a smokeless tobacco product must be made from amaterial that withstands the degradation induced by the moisture of thetobacco product itself during the whole storage period, at least to suchan extent that any change in the mechanical properties of the pouchmaterial does not compromise the quality of the tobacco product. It iswell-known that the moisture content varies with different tobacco typesand products, and also the intended shelf life may vary. A pouch for asmokeless tobacco product must therefore be tailored for the specifictobacco product, including the intended shelf life, of which the pouchis a part. This is in particular true when the pouch is made from one orseveral degradable polymers, because any change in mechanical propertiesof the pouch, such as strength or stiffness, is not to be regarded as ageneral feature among the polymers, and will be different from materialto material even if their relative degradation is the same.Consequently, specific knowledge of the general degradationcharacteristics of the polymer(s) is required to design a pouch materialthat will withstand the maximal allowed storage time for any specificsmokeless tobacco product.

In passing it may be mentioned that the time period during which aconsumer actually enjoys the smokeless tobacco product is relativelyshort, approximately 10 to 30 minutes, in particular in comparison withthe intended shelf life, which can range from 3 to 12 months; andnormally this relatively short time period during which the tobaccoproduct is in the user's mouth does not come into consideration whenselecting a suitable pouch material.

Degradable pouch materials whose degradation predominantly is induced byhumidity—or more precisely by the water that is abundant in humidair—are typically polymers characterized by having hydrolysable bonds inthe backbone of the polymer chain. Examples of hydrolysable bonds arethose found in the polymer groups comprising polyanhydrides, polyesters,polycarbonates, polyorthoesters, polyphosphazenes, polyesterurethane,polycarbonateurethane, and polyaminoacids. More specifically, polyestersor polycarbonates made through ring-opening polymerization of themonomers generally known as lactones is of particular applicability. Thelactones may be un-substituted or substituted, and some non-limitingexamples of lactones that can be used are propiolactone, pivalolactone,β-butyrolactone, 6-valerolactone, glycolide, L-lactide, D-lactide,mesolactide, paradioxanone, trimethylene carbonate, ε-caprolactone, and1,5-dioxepan-2-one. Also the dimeric lactones from ε-caprolactone and1,5-dioxepan-2-one are readily polymerized into polymers with highmolecular weight.

The aforementioned examples of lactone monomers can furthermore be mixedwith each other during the polymerization step to create block or randomcopolymers with a wide spectrum of properties. The various homopolymersand copolymers from the aforementioned monomers can furthermore beblended with each other or with any polymer of the aforementionedpolymer groups in a variety of different proportions to furtherfine-tune some of the desirable properties. One such property ofparticular importance is the degradation time, but also otherproperties, like strength and softness, should be considered.

Other synthetic polyesters as degradable materials for a pouch accordingto the present invention are those generally known as condensationpolymers. This group contains polyesters made from diacids and diols,and several of these polyesters are able to form fibres which willdegrade in nature. Examples of various diacids are, but not limited to,succinic, glutaric, adipic, pimelic, suberic, azelaic and sebacic acid.These acids can be polymerized in the presence of a variety of diols,such as ethyleneglycol, 1,2-propyleneglycol, 1,3-proanediol,1,4-butandiol, pentamethylenglycol, 1,6-hexanediol,1,4-cyclohexanedimethanol, or 1,4-cyclohexandiol, to form suitablematerial for a pouch according to the present invention.

In another embodiment of the present invention, the pouch is made from adegradable material having slow or very slow degradation kinetics whenexposed to humidity only, but with accelerated degradation kinetics whenalso exposed to microorganisms which are abundant in nature. Incomparison with materials that mainly degrade due to humidity, suchmaterials have an enhanced ability to preserve the mechanical integrityof a corresponding pouch over an extended time of storage. Severalmicroorganisms and especially several families of bacteria residing insoil will readily degrade synthetic polymer, and particularlypolyesters. When active microorganisms are taking part in thedegradation process, the degradation will proceed by oxidation and alsoenzymatic cleavage and not only by pure hydrolysis. This will furtherenhance the ongoing degradation process. The degradation processes ofnatural polymers like polysaccharides, proteins, and polyhydroxybutyrateincluding its various copolymers, mostly involve microorganisms, andconsequently a pouch made from such natural polymers would exhibitadvantageous properties.

For example, polyhydroxybutyrate and its various copolymers are, forexample, utilized by certain bacteria abundant in soil to store energy,and it can therefore be expected that a pouch comprisingpolyhydroxybutyrate will be quickly consumed by such bacteria. Somepolysaccarides are available in nature and can in many cases easily beformed into fibres. Examples of such natural polysaccarides are starchand chitosan. Starch is found in a variety of different crops and amongthe larger sources are corn and potatoes. Chitosan is the second mostabundant biopolymer on earth and is most readily available from shrimpand crab shell. Both starch and chitosan are easily degraded in natureby various microorganisms. Oxidative degradation by chitosan is veryfast and especially so in the presence of metal ions like iron, which isnaturally present in the environment. Non-limiting examples of proteinswhich can be used to make the pouch according to the invention and whichdegrade due to influence of microorganisms are fibrin, collagen andzein. Natural materials may further be stabilized by crosslinking withdiepoxides, dialdehydes or polycarbocylic acids to manipulatedegradation and mechanical properties of the end product. Degradation ofpolymers by sunlight and especially the ultraviolet part is also wellknown and most synthetic polymers today contain some kind of additive toavoid this type of degradation. Sunlight in combination with oxygen inair will cause oxidation of the polymer leading to chain scission andthus degradation. There is often a complex chain of chemical reactionsleading to the observed polymer chain cleavage that involves radicalsand the oxygen found in the surrounding air. When the polymer has beendegraded into smaller fragments these will be more readily available formicroorganisms, which will further degrade the material into carbondioxide and water. The process of breakdown by sunlight and oxidationalone is typically known as a rather slow process but today severalindustries have additives that will speed up the degradation in theenvironment. Various additives incorporate pre-oxidized polymers, tracemetals or metal chelates that will speed up the oxidation reactions whenthe material is exposed to sunlight. A number of additives exist on themarket, which will speed up degradation of common plastic material, suchas TDPA™ from EPI Environmental Products Inc. and Envirocare™ from CIBA.Copolymerization of ordinary vinyl monomers, ethylene and polypropylenetogether with carbon monoxide and thus introducing a keto group in themain polymer chain which is readily further oxidized has also been usedto speed up degradation of polymers in nature. The most well known photodegradable resins made from carbon monoxide is known as Ecolyte whichhas been used to modify other materials to be fully degradable whenexposed to unshielded sunlight and humidity.

Another polymer, which readily forms fibers and thin foils, ispolyvinylalcohol or its various copolymers. The biodegradation of thispolymer is well known and proceeds through oxidation and subsequentchain cleavage into smaller polymer chains. The oxidation process ismost readily performed by sunlight and soil bacteria and results in lowmolecular fragments that are water soluble and thus more susceptible tooxidation and hydrolysis, which leads to full degradation of thepolymer.

The above materials are non-limiting examples of degradable polymersthat can be used alone or in blends with each other to result in themost preferred degradation profile of the pouch. Various additives suchas oxidizers, sencitizers, and plasticizers can be employed to alter thedegradation characteristics of the material. Plasticizers such as butnot limited to various substituted or non substituted citric acidesters, such as triethyl-citrate or acetyl triethyl-citrate, andglycerol esters, such as triacetin, can be used to modify the softnessof the material to minimize the feel of the pouch once in the mouth.

The examples of materials and additives that can be used for the pouch(which is characterized by an acceptable degradation of the pouchthroughout storage and during use while being accelerated afterdisposal) are not limiting examples to achieve the most preferreddegradation profile. While the storage periods may be different and alsothe amount of moisture present, in different tobacco blends, the storagetime may affect the different materials differently and consequently thematerial selection for a suitable pouch material must be determined withthese factors in mind, e.g. a pouch made from a relatively dry tobaccoproduct with a short storage time can preferably be made from a materialcomposition having a faster degradation kinetic than a pouch that willhouse a moist tobacco product. For those materials where the primarydegradation arises from simple hydrolysis, the moisture content in thetobacco will be of primary importance for selecting the suitablematerial. The storage period is typically 3 to 12 months and degradationduring this time period should not lead to any such change in mechanicalproperties such as strength or pliability that will compromise the enduse of the pouch or how the customer perceives the pouch. After disposalof the pouch, the pouch should be disintegrated, e.g. fragmented intosmaller pieces, or fully degraded within a time period of 3 years, butmore preferably within 2 years and more preferably within a time periodof 1 year or less. Polymers of particular interest are those thatdegrade by means of sunlight and oxidation together with those thatdegrade by hydrolysis and/or in combination with micro organisms. Asnon-limiting examples of polymers that can be used to meet the variousselection criteria set forth above, the polylactide, polyhydroxybutyricacid, polycaprolactone family of polymers can be used. Theabove-mentioned polymers are only slowly degraded in a humidenvironment, a feature that can be manipulated, either accelerated orretarded, by copolymerisation or blending with synthetic or naturalpolymers. Poly-1-lactide has a degradation time of about 4 to 6 years asa pure homo polymer. As an example, the degradation time for purepolyglycolide is too short for the polymer to be of interest as the maincomponent in the pouch material, but if glycolide is used as aco-monomer in the polylactide polymerisation, the glycolide will befound as short but more easily degradable sequences within thelactide-glycolide copolymer and thus lead to a faster disintegration anddegradation of the pouch material. Non-limiting examples of othermonomers that can be used instead of glycolide to manipulate thedegradation kinetic of polylactide and polycaprolactone isparadioxanone, 1,5-dioxepan-2-one and trimethylene carbonate. Variousadditives like natural polymers like carbohydrates and proteins mayfurther be used to manipulate the degradation characteristics.

The pouch itself can be made from a fibre mat. Several techniques can beemployed to make the fibres used for production of the pouch materialsuch as melt spinning and dry or wet spinning. Typical fibre diametersespecially useful in this application are found in the range of 0.5 to50 microns, preferably in the range of 2 to 30 microns, and morepreferably in the range of 8 to 24 microns. It must be understood that amore stiff material may require a smaller diameter than a more softmaterial to obtain a pouch that does not feel hard or stiff once in themouth. The fibres can later be converted into non-woven fibre mats bywell-known techniques. Other techniques that may be used for productionof the inventive pouch material are fibre blowing or electro-spinning.In the two latter methods a fibre mat is produced at the same time thefibre is formed, and may for some materials be a more convenient methodto produce the pouch material. The thickness of the pouch material istypically in the range of 25 to 300 microns, but more preferably in therange of 75 to 150 microns. Although fibre forming processes may be aconvenient method to make the inventive pouch material, other techniquesmay be used. One such method is to make the pouch from a thin,perforated polymer foil. These thin foils can be made very flexible. Oneconvenient way to perforate the thin foil is to use electrical dischargeacross the foil area or any type of laser equipment such as carbondioxide or excimer lasers. Foils are most conveniently extruded, andduring this process several layers can be combined to achieve the rightfeel of the pouch material. Additives can also be used in one or all ofthe layers. Such additives could be any type of pharmacologicalsubstance, nicotine, nicotine extract, any type of oral health substancesuch as sodium fluoride, chlorhexidin or teeth whitening substances tomention a few. The pouch material, e.g. in the form of a fibre mat or afilm, can be formed into a pouch by well-known techniques such asfolding and subsequent welding, sewing or gluing, etc.

The pore size of the pouch needs to be adjusted to the tobacco productso that a minimum of solid particles escape the pouch but should allowfor a free exchange of water soluble substances. If very small pores areused and the material in the pouch is relatively hydrophobic, free waterflow may be hindered and larger pores may be needed. The same butopposite is true when a more hydrophilic material is used to manufacturethe pouch. Typically the porosity or transparency, i.e. the area notoccupied by any type of material is in the range of 5 to 40%, butpreferably found in the range of 10 to 30%, or more preferably in therange of 15 to 25%. The shape of the pores is not important for theproper function of the inventive pouch and may take any type of shape.It is therefore difficult to specify the dimensions of the pores,however, the area of any type of pore can easily be defined and the poresize can then be specified as the diameter of a circle with equivalentarea. The so defined equivalent pore diameter should be a maximum of 500microns and preferably less than 300 microns. Preferably, at least 50%of the porosity in the pouch is made up by pores having an equivalentdiameter of 100 microns or less.

Although the present invention has been described with reference tospecific embodiments, it will be apparent for those skilled in the artthat many variations and modifications can be done within the scope ofthe invention as described in the specification and defined withreference to the claims below.

1. A smokeless tobacco product adapted for oral administration,comprising: a permeable pouch adapted for administration into a user'smouth and adapted to be removed from the mouth and disposed in nature;and smokeless tobacco contained in the pouch, wherein the pouch is madefrom a degradable polymer whose degradation properties allow the pouchto be essentially intact until the time of disposal and allow the pouchto degrade in nature after disposal.
 2. A smokeless tobacco productaccording to claim 1, wherein the degradation after disposal mainly iscaused by water.
 3. A smokeless tobacco product according to claim 1,wherein the degradation after disposal mainly is caused bymicroorganisms.
 4. A smokeless tobacco product according to claim 1,wherein the degradation after disposal mainly is caused by sunlight. 5.A smokeless tobacco product according to claim 1, wherein thedegradation after disposal mainly is caused by oxygen.
 6. A smokelesstobacco product according to claim 1, wherein the degradation afterdisposal is caused by any combination of water, microorganisms,sunlight, and oxygen.
 7. A tobacco pouch comprising: tobacco; and apouch holding the tobacco, the pouch being biodegradable in the presenceof at least one of sunlight, microorganisms, and oxygen.
 8. A tobaccopouch as set forth in claim 7, wherein the tobacco has a moisturecontent and the pouch retains its integrity for at least 6 months in thepresence of the moisture content.
 9. A tobacco pouch as set forth inclaim 7, wherein the pouch completely encloses the tobacco with amaterial which is not dissolvable in a user's mouth.
 10. A tobacco pouchas set forth in claim 7, wherein the pouch is biodegradable in thepresence of sunlight.
 11. A tobacco pouch as set forth in claim 7,wherein the pouch is biodegradable in the presence of microorganisms.12. A tobacco pouch as set forth in claim 7, wherein the pouch isbiodegradable in the presence of both sunlight and microorganisms.
 13. Atobacco pouch as set forth in claim 7, wherein the pouch comprises apolymer.
 14. A tobacco pouch as set forth in claim 7, wherein the pouchis biodegradable in the presence of oxygen.
 15. A tobacco pouch as setforth in claim 7, wherein the pouch is biodegradable in the presence ofboth sunlight and oxygen.
 16. A tobacco substitute product adapted fororal administration, comprising: a permeable pouch adapted foradministration into a user's mouth and adapted to be removed from themouth and disposed in nature; and a tobacco substitute contained in thepouch, wherein the pouch is made from a degradable polymer whosedegradation properties allow the pouch to be essentially intact untilthe time of disposal and allow the pouch to degrade in nature afterdisposal.
 17. A pouch for containing tobacco or a tobacco substitute,comprising: a permeable pouch adapted for administration into a user'smouth and adapted to be removed from the mouth and disposed in nature,wherein the pouch is made from a degradable polymer whose degradationproperties allow the pouch to be essentially intact until the time ofdisposal and allow the pouch to degrade in nature after disposal.
 18. Apouch as set forth in claim 17, wherein the permeable pouch comprises afibre mat.
 19. A pouch as set forth in claim 17, wherein the permeablepouch comprises a film.
 20. A pouch as set forth in claim 17, whereinthe permeable pouch comprises a non-woven fibre mat.
 21. A pouch as setforth in claim 17, wherein the permeable pouch comprises a perforatedpolymer foil.
 22. A pouch as set forth in claim 17, wherein thepermeable pouch comprises a foil.
 23. A tobacco pouch comprising tobaccoand a pouch containing the tobacco, the pouch being made from a polymerwhich is biodegradable in the presence of at least one of sunlight,microorganisms, oxygen, and water.